docs: def _generate_energy_edges_single(ene):
      """Generate energy edges for single group"""
      midene = np.sqrt((ene[1:] * ene[:-1]))
      elo, ehi = np.zeros(len(ene)) * ene.unit, np.zeros(len(ene)) * ene.unit
      elo[1:] = ene[1:] - midene
      ehi[:-1] = midene - ene[:-1]
      elo[0] = ene[0] * (1 - ene[0] / (ene[0] + ehi[0]))
      ehi[-1] = elo[-1]
      return u.Quantity([elo, ehi])